Page 1430 - 5G Basics - Core Network Aspects

3 Signalling aspects

Figure 6-1 – Scenario and use case of this Recommendation

The unified intelligent IPv6 deployment scenario offers end-to-end service deployment and management.
The residential gateway (RG), the IP edge and the service edge are flow-forwarding enabled. The hardware
can be unified for different IPv6 transition technologies via flow-forwarding. IPv6 transition technologies can
be plugged into the controllers. The flow-forwarding enabled devices do not need to change during the
various stages of IPv6 transition.
The northbound interface is essential to support the eco-system of software-defined networking (SDN) by
allowing various SDN-related applications to be plugged in various vendor controllers. The goal is to make
the controller controlled infrastructure to be an open platform for more innovations by allowing applications
to be developed with the best network support.
Several OpenFlow switches are deployed and located at the edge of network, as shown in Figure 6-1. The
OpenFlow protocol may be extended mainly to support an IP tunnelling approach for transition purposes.
The OpenFlow switches process the incoming packets based on the flow tables delivered by the SDN
controller upon the request of an IPv6-transition application (App).

The controller in the control layer provides an interface to the IPv6 transition App, enabling it to modify traffic
processing using OpenFlow. Specifically, the controller provides an OpenFlow driver that enables the IPv6
transition App to instruct all SDN-enabled device how to treat traffic, thus making it possible to flexibly
choose the particular transition mechanism to be applied, and to select the parameters governing it. The
OpenFlow driver includes OpenFlow protocol specific tasks: listens for OpenFlow connections, creates the
channel, keeps alive, proxy between the OpenFlow wire format and the solution internal information
representation (e.g., rules, events). It is a basic function of the SDN controller.
The process shown for this case is generic. A flow can be identified by part of the layer 2 (L2) to layer 4 (L4)
packet header information. For example, all packets to a particular subscriber can be treated as belonging to
the same flow in an SDN-enabled network.
SDN provides a programmable platform for service deployment which can reduce new issues arising in the
IPv6 transition.

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